Extraction procedure for organotin analysis in plant matrices: optimisation and application

Analysis of organotin compounds in vegetal samples is not well documented, and no specific extraction procedure of those species from vegetal matrix can be found in the literature. In order to develop such a procedure, we have compared in a first step the performances of six extracting solutions based on HCl, CH3COOH, NaOH, TMAH, enzymatic mixture and ethyl ethanoate. HCl-based extraction gives the highest recoveries. The whole extraction process was then optimised by investigating the influence of all the operating parameters. The resulting method, allowed a 100% recovery of tribultyltin and triphenyltin in spiked vegetal powders, without any noticeable degradation. The optimised extraction procedure was applied to the speciation of organotins in French beans and algae. Several μg (Sn) kg−1 of butyltins were found in algae collected in an urban treatment plant and contents up to 800 μg (Sn) kg−1 were detected in French beans cultivated with polluted nutritive solution. These results highlight the existence of a transfer of organotins from polluted waters to plants.